Sonic washer



May 23, 1961 L. GELFAND ETAL SONIC WASHER Filed Jan. 11, 1957 o o o o o o o o o o o o o :jnooooooooooooef k & J INVENTORS Lou/s Ge/fana' George 8. Long The/r Affor ney 5 SONIC WASHER Louis Geliand, Detroit, Mich, and George B. Long,

Dayton, Ohio, assignors to General Motors Corporaion, Detroit, Mich, a corporation of Delaware Filed Jan. 11, 1957, Ser. No. 633,d47

6 Claims. (Cl. 683) This invention relates to a domestic appliance and more particularly to ultrasonic cleaning.

it has been customary to clean by the use of sprays or the agitation of liquid and/or particles to be cleaned. While this type of cleaning is generally satisfactory, it is slow and does not always reach all the crevices and areas hard to reach. Many parts have been rapidly cleaned successfully in liquid by ultrasonic or high frequency vibration of the liquid. However, the cost of this apparatus has been high and this tends to limit any immediate usage on a wide scale.

it is an object of this invention to provide a lower cost ultrasonic cleaner.

It is another object of this invention to provide an ultrasonic cleaner in which only a low-power oscillator is required for effective cleaning throughout a considerable space.

It is another object of this invention to provide a varying frequency ultrasonic cleaner for providing a continuously varying pattern of standing waves.

These and other objects are attained in the form shown in the drawings in which a low-power ultrasonic oscillator is connected through a multi-position motorized rotary contactor selectively with a plurality of ultrasonic transducers effectively distributed in the liquid of a dishwasher or clothes washer. In one form, all of the transducers operate at substantially the same frequency while in another form the transducers operate at different frequencies to continuously vary the standing waves to obtain a uniform average distribution of intensity. Also, various types of soil sensitive to different frequencies are more rapidly and more uniformly removed.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred form of the present invention is clearly shown.

In the drawings:

Figure 1 is a diagrammatic View and wiring diagram of an ultrasonic dishwasher embodying one form of my invention;

Figure 2 is a diagrammatic modification of Figure 1 showing the application of the transducers to a clothes washing machine; and

Figure 3 is a diagrammatic view of a modified form of ultrasonic cleaning in which a number of transducers of different frequencies are selectively connected to the same oscillator having a multiple frequency output.

Referring now to the drawings and more particularly to Figure 1 there is shown an ultrasonic dishwasher including the liquid container provided with a dish rack 22 for supporting the dishes 24 and the tumblers 26 to be cleaned. in the lower portion of the container beneath the liquid level 28 of the cleansing liquid are a plurality of relatively small low-power transducers 30 each of which may be an inexpensive low-power agitating crystal oscillator. These transducers are located and directed in such a way that they would cover and extend their cleaning power and their vibrations to the entire atent O 2,985,003 Patented May 23, 1961 space in which the dishes are located. As shown, there are six of the transducers 30. Each of these transducers 30 is connected by a conductor and a variable inductance 32 to one of the stationary contacts 34 of a rotary contactor 36 having a rotary contact 38 rotated by the electric motor 40 selectively connecting one at a time with each of the transducers 30.

The second terminal of each of the transducers 30 is connected to a common conductor 42 connecting with a low-power vacuum tube type ultrasonic oscillator designated by the reference character 44. This oscillator 44 may include a power supply connection 46, an on-ofif knob 48, a rough frequency matching control 50, a frequency indicator 52, and an intensity control 54. The oscillator 44 has an output connection 56 connecting with the rotary contact 38.

The knob 50 is used to adjust the oscillator 44 substantially to the frequency desired. The variable inductances 32 are used as trimmers to bring the oscillator 44 and each of the transducers 30 into a frequency match. The motor 40 rotates the contact 38 into engagement with each of the contacts 34 consecutively so that the individual transducers 30 are consecutively energized to impart ultrasonic waves to all parts of the liquid in the container 20 and Wash the dishes on the rack 22. This is accomplished rapidly and thoroughly.

In Figure 2, there is shown a modified form applied to a clothes Washing machine containing a rotatable perforated container 112 in which the clothes are held. The clothes container 112 is surrounded by a liquid container 121. Within the container 121 are a number of transducers which correspond to the transducers $0 in Figure 1. These transducers 130 are similarly connected by variable inductances and a rotary contactor selectively into connection with a low-power ultrasonic oscillator similar to that shown in Figure 1. The transducers 130 are likewise consecutively energized to impart ultrasonic waves to the cleansing liquid and the clothes in the container 112.

In Figure 3, the container 220 containing cleansing liquid up to the level 228 is provided with a plurality of transducers 230 of different frequencies. These transducers 230 may for example be individual crystal oscillators of different sizes and shapes in order to operate at different frequencies so as to better clean different types of soil which are more susceptible to different frequencies., The varying of the frequencies materially varies the standing wave pattern within the bath. Areas of high and low intensities are often interchanged to provide a more uniform average intensity. These transducers 230 are connected by a common conductor 242 to a multiple frequency ultrasonic vacuum tube oscillator 244. The transducers 230 are also individually connected by individual conductors 231 to different power output connections of the low-power oscillator 244. Each output connection is provided with its own individual power output control 253. These power output controls may include a variable inductance and intensity and frequency controls providing trimmers for matching purposes between the individual transducers 230 and the individual output circuits of the low-power oscillator 244. When frequencies of the individual power outputs are each individually matched with the frequencies of the associated transducers, the transducers operate at maximum amplitude of vibration and maximum efficiency.

The low-power oscillator 244 may include vacuum tube circuits feeding a coil 264) provided with four different taps 268 connected to four contacts 234 located in equal spaced relation about the axis of the motor contactor designated by the reference character 240. This motor contactor includes a rotary sector shaped contact 238. The contactor also includes a second set of four contacts 235 also located 90 apart from each other spaced in-between the contacts 234. The rotary contact 238 is a bridging contact which selectively bridges the contacts 234 and 235 to selectively energize each of the different frequency transducers 230. This continuously varies the frequency and continuously varies the standing wave pattern to provide a uniform average distribution of intensity. Thus by this arrangement, the oscillator 244 need have only sufiicient power to provide the power for one of the transducers 230 at a time. In this way only a relatively low-power oscillator is required thereby keeping the initial cost relatively low and yet good average distribution of the high frequency waves in the container 220 is provided by providing an adequate number of effectively located different frequency transducers which provide a continuous varying of the standing wave pattern.

While I have shown this system as applied to dishwashers and clothes washers, it should be understood that this cleaning system can also be applied to the cleaning of other parts and materials.

While the form of embodiment of the invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, as may come within the scope of the claims which follow.

What is claimed is as follows:

1. In a cleaning machine for articles including a liquid container adapted to contain the articles and a cleansing liquid, aplurality of individual ultrasonic transducers associated with and effectively distributed relative to the liquid container to transmit their vibrations to any foreign matter adhering to the articles, a low power high frequency oscillator having insufiicient power to simultaneously oscillate all of said ultrasonic transducers at maximum effectiveness, a selector switch means consecutively connecting said low power oscillator with each of said individual transducers, and means for continuously operating said selector switch means in continuous cycles to consecutively operatively connect said low power oscillator with each of said individual transducers.

2. In a cleaning machine for articles including a liquid container adapted to contain the articles and a cleansing liquid, a plurality of individual ultrasonic transducers associated with and effectively distributed relative to the liquid container to transmit their vibrations to any foreign matter adhering to the articles, a low power high frequency oscillator having insufiicient power to simultaneously oscillate all of said ultrasonic transducers at maximum effectiveness, individual frequency matching controls for said individual transducers, and a continuously operable power operated selector switch means for connecting said low power oscillator consecutively with each individual transducer in repeated cycles.

3. A cleaning machine for articles including a liquid container adapted to contain the articles and a cleansing liquid, said container being provided with a plurality of different individual ultrasonic transducers having different frequencies of operation and being effectively distributed relative to the liquid container to transmit their vibrations to any foreign matter adhering to the articles, a low power high multi-frequency oscillator having means to generate electric energy at a plurality of high frequencies matched to the frequencies of the individual transducers, said low power oscillator having insufiicient power to simultaneously oscillate all of said transducers at maximum effectiveness, and a continuously operable selector control switch means selectively rendering effective and selectively operably connecting the matching frequency output of said low power oscillator and each of the corresponding frequency individual transducers in repeated cycles.

4. A cleaning machine for articles including a liquid container adapted to contain the articles and a cleansing liquid, said container being provided with a plurality of different individual ultrasonic transducers having difierent frequencies of operation and being effectively distributed relative to the liquid container to transmit their vibrations to any foreign matter adhering to the articles, a low power high frequency oscillator, a plurality of trimmers and power outputs individually connected to and individually adjusted to match the oscillator to the respective individual transducers, and a continuously operable selector control switch means connected between said low power oscillator and said outputs selectively rendering effective and selectively operably connecting said outputs and each of said individual transducers in repeated cycles.

5. In combination, a plurality of different individual ultrasonic transducers having different frequencies of operation, a low power high frequency oscillator, a plurality of trimmers and power outputs individually connected to and individually adjusted to match the oscillator to the respective individual transducers, a selector switch means consecutively connecting said low power oscillator with each of said outputs, and means for continuously operating said selector switch means to provide continuous cycles of consecutive connections between said oscillator and said transducers.

6. In a cleaning machine for articles including a liquid container adapted to contain the articles and a cleansing liquid, a plurality of individual ultrasonic transducers associated with and effectively distributed relative to the liquid container to transmit their vibrations to any foreign matter adhering to the articles, a low power high frequency oscillator having insuflicient power to simultaneously oscillate all of said ultrasonic transducers at maximum effectiveness, individual frequency matching control for said individual transducers, and a continuously operable power operated selector switch means for connecting said low power oscillator consecutively with each individual transducer.

References Cited in the file of this patent UNITED STATES PATENTS 2,468,550 Fruth Apr. 26, 1949 2,578,505 Carlin Dec. 11, 1951 2,680,239 Daniels et al. June 1, 1954 2,702,260 Massa Feb. 15, 1955 2,745,998 McPherson May 15, 1956 2,802,476 Kearney Aug. 13, 1957 2,848,672 Harris Aug. 19, 1958 2,848,890 Sheldon Aug. 26, 1958 FOREIGN PATENTS 648,609 Great Britain Jan. 10, 1951 

